Accident prevention system and a vehicle including the accident prevention system

ABSTRACT

A vehicle  12  having an accident prevention system  10  that is useful for preventing an accident where a vehicle that is reversing at low speed collides with a person, is disclosed. The system  10  includes a sensor arrangement  14  for sending an object within range behind a rear end  38  of the vehicle  12  and generating an object recognition signal. The sensor arrangement  14  includes passive IR sensors  15  or reflected pulse sensors such as sonar or radar sensors  50  on the rear end  38.  A controller  20  generates an accident prevention response signal when the sensor arrangement  14  generates an object recognition signal. A brake applicator  26  is operatively coupled to a foot brake  42  to cause the vehicle  12  to stop when the controller  20  generates a response signal. The system also includes an alarm when the controller  20  generates a response signal.

CROSS-REFERENCE TO RELATED APPLICATION

The present Application is a continuation of U.S. patent applicationSer. No. 13/447,159 titled “An Accident Prevention System and a VehicleIncluding the Accident Prevention System,” filed Apr. 13, 2012 whichclaims the benefit of Australian Provisional Patent Application No.2011902483 titled “An Accident Prevention System and a Vehicle Includingthe Accident Prevention System,” filed Jun. 24, 2011, the contents ofwhich are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to an accident prevention system for use onvehicles and to a vehicle including the accident prevention system. Thisinvention also relates to a method of preventing an accident when avehicle collides with an object.

This invention relates particularly but not exclusively to an accidentprevention system for preventing a small child or animal being run overby a motor vehicle that is reversing at low speed on a travel surfacesuch as a driveway. It will therefore be convenient to hereinafterdescribe the invention with reference to this example application.However at the same time it is to be clearly understood that theinvention is capable of broader application. For example the inventionextends to all forms of vehicles and not just motor vehicles. It alsoextends to a system for preventing reversing accidents with inanimateobjects such as posts and walls. It is not limited to a system forpreventing reversing accidents involving small children.

DEFINITIONS

In this specification the term ‘reversing accident’ will be used todescribe and define a motor vehicle accident that occurs when a vehicletravelling at low speed in reverse gear collides with an object or aperson or an animal It includes a vehicle accident in a drivewayinvolving a small child but is not limited to this class of accidents.

In this specification the term ‘accident prevention’ shall be understoodto mean a system that is useful in helping to prevent accidents. Howeverit is to be clearly understood that it does not mean that it is capableof preventing all accidents from occurring. In reality it helps to avoidaccidents or resists accidents but does not eliminate the chance of anaccident completely.

In this specification the term ‘mammal’ shall be understood to mean anywarm blooded creature that meets the scientific definition of a landmammal but excluding mammals that live in water.

In this specification the term ‘heat sensor’ shall be interpreted tomean a passive IR sensor that can sense IR radiation or heat generatedby a mammal such as a human being or an animal such as a dog or cat.Such mammals have a body temperature in the range of 35 to 39 degreesCelsius.

In this specification the term ‘IR sensing zone’ shall be interpreted tomean a zone extending away from the IR sensor/s within which a mammalwill be sensed by the sensors.

BACKGROUND TO THE INVENTION

Motor vehicles and particularly motor cars are a ubiquitous feature ofmodern society that is widely used to convey people and goods from onelocation to another. They provide people with an independence ofmobility and travel that is desirable in a modern society. Vehicles areoften parked in a parking zone that is a garage or parking bay when theyare not being used. In many cases the parking zone opens onto a drivewaywhich in turn leads to a road. Often the parking zone and driveway arenot fenced off from an adjacent garden and they have open access to theland or garden around a house that is associated with the driveway. Thatis the garden opens onto the parking zone and driveway without anypedestrian barrier therebetween.

In these situations it is sometimes necessary to reverse the vehicle outof the parking zone along a driveway leading to an adjacent road. Thevehicle is driven in reverse at low speed in reverse along the drivewayto the street where it can be driven in the normal way. To reverse thevehicle the driver engages reverse gear, turns their head around andlooks through the back window at the ground or support surface behindthe vehicle. One problem is that the driver's view of the drivewaybehind the vehicle is very limited and they do not have a full anduninterrupted view of the vehicle's travel path. Accident statisticsshow that many motor vehicle accidents occur in this situation.

In one class of reversing accidents a driver will collide with aninanimate object such as a wall or post. While such accidents causedamage to physical objects which entail an economic cost they do notcause any human trauma. In another more problematic category ofreversing accidents a driver will collide with a small child or smallanimal. The child or animal is usually positioned behind the vehicle andis not seen by the driver when they reverse the vehicle. If it is ayoung child, the child is often too young to be aware of the danger tothem posed by the reversing vehicle. Consequently they usually do nottake any avoiding action. Sometimes the driver does not see the childbecause they have limited vision through the rear window of the vehicle.Further some drivers find it awkward to turn around and look through therear of the vehicle and sometimes do not even bother to do this. Yetfurther the driver might not thoroughly and carefully check that thearea behind the vehicle is clear people before the vehicle startsreversing. Yet further sometimes driver simply start reversing and hopethat anyone in the way will take avoiding action.

Applicant understands that reversing car accidents cause about 229fatalities a year in the USA. They cause about 12 fatalities a year inAustralia and about 4 fatalities a year in New Zealand. JeanetteFennell, who is the founder and co-president of the non-profitfoundation Kidsandcars.org, advises that about 50 children each week inthe USA are the victims of reversing car accidents. Of these 48 childrenare treated in emergency rooms and 2 are killed. Further statistics showthat children under the age of three years are those most likely to bethe victims of reversing car accidents. Further where the children arenot killed in these accidents they usually sustain severe head, chest orlower limb injuries. The statistics reveal that the driver of thereversing vehicle is usually driving very slowly when the accidentoccurs. Further the driver of the vehicle is usually a parent, familymember or friend of the child that is run over which adds to the traumacaused by these accidents.

FIG. 1 of the drawings illustrates one example scenario in which a youngchild is seated on the ground playing with a toy just behind a motorvehicle that is about to reverse out of a driveway. The small child isseated on the ground close to the back of the vehicle and is centrallypositioned with respect to the vehicle. This makes it virtuallyimpossible for the driver to see the child from their position seated inthe driver's seat of the vehicle even if they are diligent. Accordinglyunless someone outside the vehicle alerts the driver to the presence ofthe small child, or the driver actually sees the child in this positionprior to getting into the vehicle, there is a real risk of the childbeing run over by the reversing vehicle.

FIG. 2 of the drawings illustrates another example scenario in which ayoung child could be run over by a reversing vehicle. As shown in thedrawings the child is riding a tricycle on a hard paved surface of adriveway just behind the vehicle. The child has a very low profile orheight and is thus not easily visible to a driver of the reversing motorvehicle. The situation is exacerbated by the fact that the child on thetricycle is constantly moving about as distinct from being in a fixedposition. Thus a driver may think the child is positioned outside of areversing zone or travel path of the vehicle when they reverse thevehicle when that is not the case.

The applicant is aware of some prior art efforts that have been made toassist a driver of a motor vehicle to reduce the risk of a reversingaccident occurring. One prior art attempt to address this probleminvolves the use of reversing cameras that are either integrated into avehicle at the time of manufacture or supplied as an after-marketproduct. The reversing cameras project a visual image of the reversingzone behind the vehicle. The reversing cameras are mounted on the rearof a vehicle and are operatively coupled to an LED screen that ismounted within the cabin of the motor vehicle in a position in which itis visible to the driver. Some screens are mounted on the dashboardwhile other screens have been mounted on the rear view mirrors. The ideais that the image of the area behind the vehicle can then be observed bya driver when they reverse the motor vehicle. These types of deviceshave been around for some time and can be retrofitted to existingvehicles. They are designed to assist a driver when parking theirvehicle. Sonar parking sensors work by sending out sound pulses fromsensors mounted in the rear of the vehicle. The sonar pulse bounces offan object and returns to the sensor and a CPU associated with the sensormeasures the time taken for the sound wave to return to the sensor. Thisprovides a measure of the distance of the object away from the sonarsensor and thereby the rear of the vehicle. When the calculated distancecomes within a predetermined range then the CPU sends a signal to analarm inside the cabin of the vehicle to alert the driver to theexistence of an object within a range of the rear end of the vehicle.However in the Applicant's view this prior art product has not been verysuccessful. Applicant is aware of a number of instances a motor vehicleequipped with reversing cameras and sonar parking sensors has run over achild. That is the cameras of the reversing zone and the image of thereversing zone displayed within the driver's cabin of the vehicle didnot operate or intervene to prevent an accident. Yet further Applicantbelieves that sonar parking sensors are not very reliable and are oftenignored by the driver and cannot be fitted to a vehicle that is used fortowing a boat, trailer or caravan.

Applicant believes that one problem of this prior art system is thatwhen a person is driving a vehicle in reverse their head is turnedaround and they are looking out of the rear window of the vehicle.Consequently they are not able to look at a display screen mounted onthe dashboard because this would require their head to face forwards.The technique whereby a driver turns their head around is shown in FIG.3 of the drawings.

Further if a driver is in a hurry when they reverse a car out of aparking bay or driveway, they may not take the time to carefully checkthe image on the screen generated by the reversing cameras before theystart moving. Once they have started moving it is difficult to look atthe screen on the dashboard when their head is turned around facing outof the back of the motor vehicle. Yet another problem identified by theApplicant is that drivers are often distracted by mobile phones, radioor music within the car and/or other passengers within the car andeither cannot hear the parking sensor alarms or ignore the parkingsensor alarms. In summary the prior systems described above rely solelyand exclusively on the actions and behaviour and ability of the driverand they have been found to be wanting. Further these systems do notwarn anybody outside of the vehicle of an imminent danger of acollision.

Clearly it would be advantageous if a contrivance and/or a method couldbe devised that was able to effectively reduce the number of reversingaccidents involving small children. This would reduce the amount of roadtrauma including death and serious injury involving small children andwould undoubtedly have a significant benefit to society. This isparticularly the case when one recognizes that very often the childrenare run over by a close friend or parent.

SUMMARY OF THE INVENTION

According to one aspect of this invention there is provided an accidentprevention system for use on a vehicle having a front end and a rearend, the accident prevention system including:

a sensor arrangement for mounting on the vehicle for sensing an objectrearward of the rear end of the vehicle, and that generates an objectrecognition signal when it senses an object satisfying a certaincondition;

a controller that is operatively coupled to the sensor arrangement andthat generates an accident prevention response signal on receiving anobject recognition signal from the sensor arrangement; and

a brake applicator that is operatively coupled to a brake of the vehiclein use, the brake applicator is operatively connected to the controllerand applies the brake of the vehicle when the controller generates asaid accident prevention response signal whereby to resist movement ofthe vehicle.

The sensor arrangement may include an IR sensor arrangement that sensesIR heat and that generates an object recognition signal when it sensesan object satisfying the condition that it radiates IR heatcorresponding to a mammal, and sends it to the controller.

The IR sensor arrangement may comprise at least one IR sensor that ismounted on the rear end of the vehicle, e.g. a single IR sensor mountedon the rear end or a plurality of IR sensors that are spaced apartacross the rear end of the vehicle.

The sensor arrangement may include a reflected pulse sensor arrangementthat transmits pulses of electromagnetic radiation away from the rearend of the vehicle and senses return pulses returning to the sensorarrangement. The sensor arrangement may generate an object recognitionsignal when it senses an object satisfying the condition that it iswithin a certain range of the rear end of the vehicle, and sends theobject recognition signal to the controller.

The reflected pulse sensor arrangement may generate an objectrecognition signal when it identifies objects within a range that is adistance of less than 2.0 m (metre) of the rear end of the vehicle, e.g.within a range that is a distance of 1.0 m to 2.0 m of the rear end ofthe vehicle, e.g. a distance of 1.0 m to 1.5 m.

The reflected pulse sensor arrangement may comprise one or morereflected pulse sensors that are positioned on the rear end of thevehicle.

The one or more reflected pulse sensors may comprise sonar sensors thatpulse sound waves and sense when the sound waves return to the sensorarrangement. Instead the reflected pulse sensor arrangement may comprisea radar sensor arrangement that pulses radio waves and senses when theradio waves return to the sensor arrangement. Further instead thereflected pulse sensor arrangement may comprise a microwave sensorarrangement that pulses microwaves and senses when they return to thesensor arrangement.

The sensor arrangement may include: an IR sensor arrangement that sensesIR heat and that generates an object recognition signal when it sensesan object satisfying the condition that it radiates IR heatcorresponding to a mammal, and sends it to the controller; and areflected pulse sensor arrangement that transmits pulses ofelectromagnetic radiation away from the rear end of the vehicle andsenses return pulses returning to the sensor arrangement, and the sensorarrangement generates an object recognition signal when it senses anobject satisfying the condition that it is within a certain range of therear end of the vehicle, and sends the object recognition signal to thecontroller.

The IR sensor arrangement may comprise one or more passive IR sensorsand the reflected pulse sonar arrangement may comprise a plurality ofsonar sensors.

The brake applicator may include a solenoid that is operativelyconnected to the controller, a brake mounting member and a cableoperatively coupling the brake mounting member to the solenoid.

The accident prevention system may further include an alarm that isoperatively connected to the controller, and the alarm may issue analarm signal on receiving an accident prevention response signal fromthe controller. The alarm may include a siren that issues an audio alarmsignal and the alarm may further include a visual alarm in the form of aflashing light that is visible to persons outside of the vehicle.

The controller may be a central processing unit contained within acontrol housing, and the CPU may be wired to the sensor arrangement andthe CPU may be wired to the brake applicator and to the alarm.

The brake applicator may be operatively mounted on the operating footbrake of the vehicle that is used when the vehicle is driven on theroad. Instead the brake applicator may be operatively mounted on anotherbrake of the vehicle such as a park brake, e.g. a hand operated parkbrake or a foot operated park brake.

According to another aspect of this invention there is provided anaccident prevention system for use on a vehicle having a front end and arear end, the accident prevention system including:

a sensor arrangement for mounting on a motor vehicle for sensing anobject rearward of the rear end of the vehicle, and that generates anobject recognition signal when it senses an object satisfying a certaincondition; and

a controller that is operatively coupled to the sensor arrangement andthat generates an accident prevention response signal on receiving anobject recognition signal from the sensor arrangement.

The sensor arrangement may include an IR sensor arrangement that sensesIR heat and that generates an object recognition signal when it sensesan object satisfying the condition that it radiates IR heatcorresponding to a mammal, and sends it to the controller. The IR sensorarrangement may include any one or more of the features of the IR sensorarrangement defined in the preceding aspect of the invention.

The sensor arrangement may also include a reflected pulse sensorarrangement that transmits pulses of electromagnetic radiation away fromthe rear end of the vehicle and senses return pulses returning to thesensor arrangement. The sensor arrangement may generate an objectrecognition signal when it senses an object satisfying the conditionthat it is within a certain range of the rear end of the vehicle, andsends the object recognition signal to the controller.

The reflected pulse sensor arrangement may be a sonar pulse sensorarrangement, a radar pulse sensor arrangement or a microwave pulsesensor arrangement. In particular the reflected pulse sensor arrangementmay include any one or more of the features of the reflected pulsesensor arrangement defined in the preceding aspect of the invention.

The accident prevention system may include a brake applicator that isoperatively coupled to a brake of the vehicle in use, the brakeapplicator is operatively connected to the controller and applies thebrake of the vehicle when the controller generates a said accidentprevention response signal whereby to resist movement of the vehicle.The brake applicator may include any one or more of the features of thebrake applicator defined in the preceding aspect of the invention.

According to another aspect of this invention there is provided avehicle having an accident prevention system installed thereon, thevehicle including:

a vehicle body having a front end and a rear end mounted on groundengaging formations that permit the vehicle body to travel across asurface, the vehicle including at least one brake for stopping thevehicle;

a sensor arrangement mounted on the vehicle for sensing an objectrearward of the rear end of the vehicle, and that generates an objectrecognition signal when it senses an object satisfying a certaincondition;

a controller that is operatively coupled to the sensor arrangement andthat generates an accident prevention response signal on receiving anobject recognition signal from the sensor arrangement; and

a brake applicator that is operatively coupled to a said brake, thebrake applicator is operatively connected to the controller and appliesthe brake when the controller generates a said accident preventionresponse signal whereby to resist movement of the vehicle.

The sensor arrangement may include an IR sensor arrangement that sensesIR heat and that generates an object recognition signal when it sensesan object satisfying the condition that it radiates IR heatcorresponding to a mammal, and sends it to the controller. In particularthe IR sensor arrangement may comprise at least one IR sensor that ismounted on the rear end of the vehicle.

The sensor arrangement may include a reflected pulse sensor arrangementthat transmits pulses of electromagnetic radiation away from the rearend of the vehicle and senses return pulses returning to the sensorarrangement. The sensor arrangement generates an object recognitionsignal when it senses an object satisfying the condition that it iswithin a certain range of the rear end of the vehicle, and sends theobject recognition signal to the controller.

The reflected pulse sensor arrangement may generate an objectrecognition signal when it identifies objects within a range of lessthan 2.0 m of the rear end of the vehicle. In particular the reflectedpulse sensor arrangement may generate an object recognition signal whenit identifies objects within a range that is a distance of 1.0 m to 2.0m of the rear end of the vehicle, e.g. a distance of 1.0 m to 1.5 m.

The reflected pulse sensor arrangement may comprise one or morereflected pulse sensors that are positioned on the rear end of thevehicle.

The one or more reflected pulse sensors may comprise sonar sensors thatpulse sound waves and sense when the sound waves return to the sensorarrangement. Instead the reflected pulse sensor arrangement may comprisea radar sensor arrangement that pulses radio waves and senses when theyreturn to the sensor arrangement. Further instead the reflected pulsesensor arrangement may comprise a microwave sensor arrangement thatpulses microwaves and senses when they return to the sensor arrangement.Yet further instead the reflected pulse sensor arrangement may utilisemany other forms of electromagnetic radiation within the electromagneticspectrum.

The sensor arrangement may include: an IR sensor arrangement that sensesIR heat and that generates an object recognition signal when it sensesan object satisfying the condition that it radiates IR heatcorresponding to a mammal, and sends it to the controller; and areflected pulse sensor arrangement that transmits pulses ofelectromagnetic radiation away from the rear end of the vehicle andsenses return pulses returning to the sensor arrangement, and the sensorarrangement generates an object recognition signal when it senses anobject satisfying the condition that it is within a certain range of therear end of the vehicle, and sends the object recognition signal to thecontroller.

In this form of the invention the IR sensor arrangement may comprise oneor more passive IR sensors and the reflected pulse sonar arrangement maycomprise a plurality of sonar sensors.

The brake applicator may include a solenoid that is operativelyconnected to the controller, a brake mounting member and a cableoperatively coupling the brake mounting member to the solenoid.

The solenoid may comprise a solenoid housing having at least electricalcoil and a plunger received within the housing. The accident preventionresponse signal from the controller may energise the electrical coil/sand displaces the plunger within the solenoid housing which in turnthrough the cable displaces the brake mounting member by a correspondingdistance and thereby applies the brake.

The accident prevention system on the vehicle may include a mechanicalarrangement that enables the solenoid plunger to be displaced intocontact with a holding coil switch whilst being attached to said cable,whereby to enable the cable to extend fully into contact with theholding coil switch when its movement is otherwise restricted.

The accident prevention system on the vehicle may further include analarm that is operatively connected to the controller, and the alarm mayissue an alarm signal on receiving an accident prevention responsesignal from the controller.

The vehicle body may include a cabin within which a driver's seat islocated, and the alarm may include a siren or horn mounted on thevehicle outside of the cabin that issues an audio alarm signal. Thealarm may further include an audio and/or visual alarm mounted on thevehicle inside the cabin. The audio alarm may make a loud noise and thevisual alarm may include a flashing light that is visible to personsoutside of the vehicle.

The sensor arrangement, the brake applicator and the alarm may includeany one or more of the features of these components as defined in thefirst aspect of the invention above.

The vehicle may be a production or factory produced production motorvehicle with its own engine that can be driven on public roads. Thebrake that is applied by the accident prevention system may be the footbrake on the vehicle that is used to stop the vehicle when it istravelling on the road.

According to another aspect of this invention there is provided avehicle having an accident prevention system installed thereon,including:

a vehicle body having a front end and a rear end mounted on groundengaging formations that permit the vehicle body to travel across asurface, the vehicle including at least one brake for stopping thevehicle;

a sensor arrangement mounted on the vehicle for sensing an objectrearward of the rear end of the vehicle, and that generates an objectrecognition signal when it senses an object satisfying a certaincondition; and

a controller that is operatively coupled to the sensor arrangement andthat generates an accident prevention response signal on receiving anobject recognition signal from the sensor arrangement.

The sensor arrangement may include an IR sensor arrangement that sensesIR heat and that generates an object recognition signal when it sensesan object satisfying the condition that it radiates IR heatcorresponding to a mammal, and sends it to the controller.

The IR sensor arrangement may include any one or of the features of theIR sensor arrangement defined in any of the preceding aspects of theinvention.

The sensor arrangement may include a reflected pulse sensor arrangementthat transmits pulses of electromagnetic radiation away from the rearend of the vehicle and senses return pulses returning to the sensorarrangement, and the sensor arrangement generates an object recognitionsignal, when it senses an object satisfying the condition that it iswithin a certain range of the rear end of the vehicle, and sends theobject recognition signal to the controller.

The reflected pulse sensor arrangement may utilise sonar waves, radiowaves, or microwaves and may include any one or more of the features ofthe reflected pulse sensor arrangement defined in any of the precedingaspects of the invention.

The vehicle may include an alarm and the alarm may include any one ormore of the features of the alarm defined in the first space of theinvention above.

According to another aspect of this invention there is provided avehicle, including:

a vehicle body having a front end and a rear end mounted on groundengaging formations that permit the vehicle body to travel across asurface, the vehicle including at least one brake for stopping thevehicle; and

an accident prevention system as defined in either of the precedingaspects of the invention.

The accident prevention system may include any one or more of theoptional or preferred features of the accident prevention system definedin any one of the previous aspects of the invention. For example thesystem may include a sensor arrangement as described in the precedingaspect of the invention, a controller as defined in the preceding aspectof the invention and a brake applicator as defined in a preceding aspectof the invention. It may also include an alarm as defined in thepreceding aspect of the invention.

According to another aspect of this invention there is provided a methodfor preventing a reversing accident where a vehicle that is reversing alow speed collides with a person in its path of travel, the methodincluding:

sensing an object rearward of a rear end of the vehicle and generatingan object recognition signal when an object is sensed that meets acertain condition; and

generating an accident prevention response signal on receiving an objectrecognition signal from the sensor arrangement, the accident preventionresponse signal response includes applying the brakes of the vehicle toeither bring it to a halt if it is reversing or to stop it fromreversing if it is stationary.

Sensing an object rearward of a rear end of the vehicle may includesensing IR heat from a mammal using a passive IR sensor.

Sensing an object rearward of a rear end of the vehicle may includetransmitting a pulse of electromagnetic radiation away from the rear endof the vehicle and sensing for return pulses that return to the sensorarrangement.

Transmitting a pulse of electromagnetic radiation away from the rear endof the vehicle may comprise transmitting a sonar pulse, a radar pulse ora microwave pulse.

Said generating an accident prevention response signal may includeissuing an alarm.

Issuing an alarm may comprise issuing an audio alarm and/or a visualalarm. Issuing an audio alarm may include issuing an audio alarm outsideof the vehicle and/or inside of the vehicle.

According to yet another aspect of this invention there is provided amethod for preventing an accident where a vehicle travelling at lowspeed collides with a person in its path of travel, the methodincluding:

sensing an object that is at risk of being run over by a vehicle andgenerating an object recognition signal when an object is sensed thatmeets a certain condition; and

generating an accident prevention response signal on receiving an objectrecognition signal from the sensor arrangement.

The method may include any one or more of the optional or preferredfeatures defined in the preceding aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

An accident prevention system for preventing low speed reversingaccidents and a vehicle incorporating the system in accordance with thisinvention may manifest itself in a variety of forms. It will beconvenient to hereinafter describe several example embodiments of theinvention in detail with reference to the accompanying drawings. Thepurpose of providing this detailed description is to instruct personshaving an interest in the subject matter of the invention how to carrythe invention into practical effect. However it is to be clearlyunderstood that the specific nature of this detailed description doesnot supersede the generality of the preceding broad description. In thedrawings:

FIG. 1 is a perspective view of a small child seated on the groundbehind a parked motor vehicle;

FIG. 2 is a perspective view of a child riding a tricycle behind aparked motor vehicle;

FIG. 3 is a perspective view of a driver reversing a motor vehicleshowing their neck rotated so that their face looks out of the rear ofthe motor vehicle;

FIG. 4A is a schematic side perspective view of a vehicle fitted with anaccident prevention system in accordance with one embodiment of theinvention and FIG. 4B is a close up of part of the vehicle shown in FIG.4A with some structural details omitted for clarity;

FIG. 5 is a schematic plan view of the accident prevention system ofFIG. 4A;

FIG. 6 is a three dimensional view of a controller forming part of theaccident prevention system of FIG. 4A;

FIG. 7 is a schematic drawing showing inputs that can be entered intothe controller and outputs that can be generated by the controller;

FIG. 8 is a three dimensional view of an audio alarm and a visual alarmfor the accident prevention system of FIG. 4A that is mounted on a rearwindow of the vehicle inside the vehicle;

FIG. 9 is a three dimensional view of an infra-red sensor and a sonarsensor forming part of the IR and sonar sensor arrangements of theaccident prevention system of FIG. 4A;

FIG. 10 is a perspective view of the brake actuator of the accidentprevention system of FIG. 4A that is connected to the brake pedal of thevehicle;

FIG. 11 is a sectional view through the electronic cylinder of the brakeactuator of the accident prevention system of FIG. 4A showing it mountedto the brake pedal of the vehicle in a ready but not activated positionand also in an activated position;

FIG. 12 is a schematic perspective view showing the vehicle of FIG. 4Afitted with the accident prevention system when the vehicle is in usereversing along a driveway when a small child is in the path of thevehicle;

FIG. 13 is a schematic side perspective view of a vehicle fitted with anaccident prevention system in accordance with another embodiment of theinvention;

FIG. 14 is a schematic side perspective view of a vehicle fitted with anaccident prevention system in accordance with yet another embodiment ofthe invention;

FIG. 15 is a schematic side perspective view of a vehicle fitted with anaccident prevention system in accordance with yet another embodiment ofthe invention;

FIG. 16 is a schematic top perspective view of the vehicle fitted withthe accident prevention system in FIG. 15;

FIG. 17 is a schematic side perspective view of a vehicle fitted with anaccident prevention system in accordance with yet another embodiment ofthe invention;

FIG. 18 is a schematic side perspective view of a vehicle fitted with anaccident prevention system in accordance with yet another embodiment ofthe invention; and

FIG. 19 is a schematic upper perspective view of a vehicle fitted withan accident prevention device in accordance with the invention towing atrailer also fitted with an accident prevention device in accordancewith the invention.

FIGS. 1 to 3 have been discussed in the background to the inventionsection above. They will not be discussed any further in this detaileddescription of the invention.

FIGS. 4A to 11 are schematic illustrations of one embodiment of anaccident prevention system in accordance with one embodiment of theinvention in use mounted on a vehicle. In these drawings the accidentprevention system is referred to by the reference numeral 10 and a motorvehicle fitted with the system is referred to generally by the referencenumeral 12.

The system 10 as shown in FIGS. 4A and 4B includes an IR sensorarrangement that is indicated generally in some of the drawings bynumeral 14 that is arranged to sense IR heat from a mammal in an IRsensing zone behind the motor vehicle 12 and to generate a mammalrecognition signal when it senses a mammal in the IR sensing zone. Thesystem 10 also includes a sonar sensor arrangement that is indicatedgenerally in some of the drawings by numeral 16 that is arranged tosense sonar waves bouncing off an object in an object sensing zone andgenerating an object recognition signal. The system 10 includes acontroller 20 that is operatively connected to the IR sensingarrangement 14 and the sonar sensor arrangement 16 that generates anaccident prevention response on receiving a mammal recognition signal oran object sensing signal from the IR sensor or sonar sensor arrangements14 or 16 respectively. Yet further the system 10 also includes an alarmthat is operatively connected to the controller 20 and which isactivated when the controller 20 issues an accident prevention response.The system 10 also includes a brake applicator 26 that is operativelyconnected to a brake of the motor vehicle 12 so that it applies thebrakes of the vehicle 12 when it is activated. The brake applicator 26is also operatively connected to the controller 20 such that the brakeapplicator 26 is activated when the controller 20 generates an accidentprevention response. Each of the components of the system is describedin more detail in turn below.

The vehicle 12 comprises a vehicle body 30 that is mounted on wheels 32.The vehicle is a road going vehicle such as a motor car with an enginereceived within an engine compartment, a driver's seat 34 within aninternal cabin 35 and a trunk or boot. The vehicle 12 is operated ordriven by a driver seated on the driver's seat 34. As shown in FIG. 5the vehicle body 30 has a front end 36 and a rear end 38 and two sides40 extending between the front and rear ends 36 and 38. The vehicle 12includes a set of driver's controls that include a foot brake 42 thatcan be applied by a driver to activate the operating brakes (as distinctfrom the park brake) of the vehicle 12 to slow down or stop the vehicle12 while it is being driven on the road. Further as shown in FIG. 12 therear end 38 has a vehicle registration plate 44 and two laterally spacedtail lights 46. The rear end also includes a bumper 48 extendingtransversely across the rear end 38 of the vehicle 12 at a height ofabout 0.3 m to 1.5 m, in particular 0.5 m to 0.9 m, above the travelsurface on which the vehicle 12 is mounted.

In the embodiment illustrated in FIG. 12, the IR sensor arrangement 14comprises a single passive thermal IR sensor 15 that is engineered tosense and identify the thermal signature of IR heat generated by a warmblooded mammal such as a human or animal having a body temperature inthe region of 36 to 38 degrees Celsius. The sensor 15 is containedwithin a small compact sensor housing that is centrally mounted on therear end 38 of the motor vehicle 12. While the illustrated sensor 15 ismounted adjacent the registration plate 44, e.g. above the numbersand/or letters on the registration plate 44, it should be understoodthat the sensor 15 can be mounted anywhere on the rear end 38. Thesensor 15 is arranged so it is directed downward while facing away fromthe rear end 38 of the vehicle 12 so it can sense a warm body in an IRsensor zone 49 that extends rearward from the vehicle 12. Applicant hasfound that it is desirable to direct the IR sensor 14 downward towardsthe ground surface to avoid false activation of the system 10 due to thedetection of other people in the environment. The IR sensor zone 49basically extends for a limited length in a direction away from thevehicle 12 along a travel path taken by a vehicle when it reverses in arearward direction. The passive IR sensor 15 can recognise the thermalsignature of a mammal that is based on the specific internal bodytemperature of a mammal Passive IR sensors are widely used on outdoorlight systems to switch on the light when the person is sensed wherethey are sometimes called ‘heat sensors’. As the structure and functionof heat sensors would be known to persons skilled in the art and thestructure and function does not form part of the invention it will notbe described further in this specification.

The sonar sensor arrangement 16 comprises a plurality of sonar sensors50 that are mounted on the rear end 38 of the vehicle 12 spaced apartfrom each other. In the illustrated embodiment they are mounted on thebumper 48 spaced apart from each other along the bumper 48. The sonarsensors 50 are capable of sensing both animate and inanimate objectswithin an object sensing zone 49 shown in FIG. 12 without being able todiscriminate between the two types of objects. They pulse sound wavesand detect reflected sound waves that return to the sensor 50 and basedon the time taken for the sound pulse to return to the vehicle 12 theycan sense the distance that the object is away from the vehicle 12. Thusit augments the sensor capability of the IR-sensor which detects mammalssuch as people because it provides another sensor type to sense a childor animal and thereby increases the reliability of the system. It alsohelps to avoid collisions with inanimate objects such as structures. Thefunctioning of the sonar sensors is indicated schematically in FIG. 12.

The system 10 is arranged so that the controller 20 issues an accidentprevention signal when the sonar sensors 50 sense an object comingwithin a predetermined distance of about 1.5 m of the rear end of thevehicle 12. Thus the sonar sensors 50 effectively sense an objectgetting closer to the rear end 38 and the system 10 and in particularthe controller 20 is engineered to generate an accident preventionsignal and apply the brakes of the vehicle 12 when the object comeswithin the predetermined distance. Thus the sonar sensors 50 operate ina fundamentally different manner to the passive IR sensor 15 whichsenses warm blooded mammals such as animals and small children withouthaving an ability to sense the distance that the object is away from thesensor 15. As the use of sonar sensors 50 is known as their structureand function would be known to a person skilled in the art they will notbe described in further detail in this specification.

In the illustrated embodiment shown in FIG. 6 the controller 20 includesa processor such as a CPU that is contained within a compact controlhousing 54 that is mounted in an easily accessible position within thetrunk or boot of the vehicle 12. Alternatively the control housing 54could be mounted in the engine compartment. The controller 20 isoperatively coupled to the IR sensor 15 by means of wiring 56 andreceives and processes signals received from the passive IR-sensor 15.In particular when the controller 20 receives a mammal recognitionsignal from the sensor 15 it generates an accident prevention responsewhich generates a number of different responses that are discussedbelow. Further the controller 20 is also operatively connected to thesonar sensors 50 by means of wiring 57, which also operatively connectsthe sonar sensors 50 to each other. In particular when the controller 20receives an object recognition signal from one or more of the sensors 50also generates an accident prevention response signal in relationthereto. The wiring 56 and 57 is shown in the drawing as a single linein the drawings because the two sets of wiring is received within asingle wiring loom.

FIG. 7 illustrates schematically the inputs that can be entered into thecontroller 20 and the outputs that can be generated by the controller 20during operation of the system 10. The main inputs shown in the drawingare the IR sensor, other sensor inputs such as the sonar sensor inputs,and the reverse input which arms the system 10 when the vehicle 12engages reverse gear as described below. Other inputs include the 12volt supply from the vehicle battery, a self-test feature that enablesthe system to be tested, and a system override. The main outputs fromthe controller 20 are the warning light, a brake actuator, an audioalarm that is a piezo siren and a piezo buzzer as shown in FIG. 7.

The system 10 has an arming arrangement shown generally by numeral 63that causes the system 10 to be armed when the vehicle 12 engagesreverse gear. In the embodiment illustrated in FIG. 4A, the armingarrangement of the system 10 is operatively coupled to an electricalcircuit within the vehicle 12 that energises the reverse lights on themotor vehicle 12 and thereby arms automatically when the vehicle 12engages reverse gear. As illustrated in FIG. 4, the system 10 also hasan override switch indicated by numeral 65 that enables a driver tooverride the system 10 by activating the override switch 65. A drivercan use this feature for example when they wish to reverse up close to awall or post and the system 10 applies the brakes 42 of the vehicle 12before the vehicle 12 can get close enough to a said post or wall. Theoverride switch 65 is located in the cabin 35 of the vehicle 12 in alocation at which it can be conveniently accessed by the driver. Forexample the override switch 65 might conveniently be mounted on thedashboard of the vehicle 12. The override switch 65 is operativelyconnected to the controller 20 by means of a wiring 68. This wayactivation of the override switch 65 sends an override signal to thecontroller 20 which in turn sends signals to the brake applicator 26 torelease the brake 42 and signal to the alarm 22 to switch off the alarm22.

The alarm arrangement can include more than one alarm device for exampleat different locations on the vehicle. The alarm arrangement includes asiren or horn 58 that is positioned outside of the cabin 35 towards thefront end 36 of the motor vehicle 12. Conveniently the siren 58 soundsto the outside of the vehicle 12 so that it is clearly audible tooutside persons including a person in the path of the reversing vehicle12. The siren 58 is operatively coupled to the controller 20 by means ofwiring 59 and when the controller 20 generates an accident preventionresponse it activates the siren 58 causing it to make a loud noise. Thesiren or horn 59 could be provided by the factory fitted horn or hooterof the vehicle 12.

In the illustrated embodiment shown in FIG. 8 the alarm arrangement alsoincludes a further alarm 60 that is mounted within the cabin 35 having aplanar backing surface up against a rear window of the vehicle 12 asillustrated in FIG. 12. The further alarm 60 is a visual and audio alarmthat is operatively connected to the controller 20 by means of wiring61. When the controller 20 generates an accident prevention responsesignal it activates the alarm 60 in the rear window of the motor vehicle12 as illustrated in FIG. 4A and causes a bright light 67 on the alarm60 to flash. The alarm 60 including light 67 positioned in the rearwindow is visible to people inside and outside of the vehicle. Furtherthe loud audio alarm positioned within the cabin 35 of the vehicle 12,in contrast to the alarm 58 which is positioned outside the cabin 35,alerts the driver of the vehicle 12 to the risk of an accident. Thewiring 61 could also cause the factory fitted horn which can be fittedin the engine compartment to sound.

FIGS. 11 and 11 illustrate the brake applicator 26 for the system 10which broadly includes a brake mounting member 70 and a solenoid 72which is operatively connected to the brake mounting member 70.

The brake mounting member 70 automatically applies or presses the pedalof the brake 42 inside the cabin 35 causing the brakes to be swiftly andfirmly applied. This stops the vehicle 12 if it is moving, or stops itfrom taking off if it has not yet started moving. The structure of thebrake applicator 26 and its manner of operation is illustrated in somedetail in FIGS. 10 and 11.

The brake mounting member 70 comprises a brake pedal mounting formationin the form of a bracket 76 that can be fixed to the brake pedal 42 inthe manner shown in FIG. 10, and a cable mounting formation 78 extendinglaterally away from the bracket 76. The applicator 26 also includes acable 80 extending from the bracket 76 of the mounting element 76 to thesolenoid 72. This way a movement of the cable 80 by the solenoid 72 actsto pull the brake pedal 42 towards the solenoid 72, i.e. in a forwarddirection, thereby applying the regular or operating brakes of thevehicle 12.

The solenoid 72 broadly comprises a solenoid housing 82 and an actuator84 that is a plunger. The solenoid 72 is mounted on the vehicle 12 at adistance spaced from the foot brake by means of a mounting bracket 86.The bracket 86 in turn can be mounted on a wall of the body of thevehicle 12 by fastening elements such as screws which are passed throughopenings 87 in the bracket 86. When the controller 20 sends an accidentprevention response signal to the solenoid 72, the coils of the solenoid72 are energised by an electrical current and the solenoid actuator 84is linearly displaced relative to the housing 82. The movement of theactuator 72 pulls the cable 80 which in turn pulls on the cable mountingformation 78 and thereby the bracket 76, to apply the brake 42 of thevehicle 12 and stop the vehicle 12. Conveniently the solenoid has a dualcoil system in which a first coil 124 can draw a substantial current inorder to generate the necessary force required to apply the brakes ofthe vehicle 12. By contrast the second coil 125 is a holding coil andrequires far less current to hold the actuator plunger 84 in placeagainst a rear of the housing 82. As the plunger 84 approaches the rearof the housing 82 it comes under the influence of and into contact witha holding coil switch 123. This switches off the first coil 124 andturns on the second coil 125. In view of the high current throughputthat is required to apply the brake a high level of use of this coil 124is unsustainable and would lead the coil 124 to fail. Therefore it isvery important for the actuator plunger 84 to make contact with theholding switch 123 to ensure that the solenoid 72 goes into holdingmode. This holds the brake 42 in the applied position until the solenoid72 receives a signal from the controller 20 to release the brakes 42.The brake applicator 26 also includes a feature that causes the solenoid72 to close properly each time it is activated even if the travel of thebrake pedal 42, when it is applied, is insufficient to displace theactuator 84 fully to a rear end of the solenoid housing 82 where it canmake good contact with the holding coil switch 123.

The cable 80 is engineered so that it has some resilience and canthereby be extended further than the travel of the brake pedal 42 toeffect good contact of the actuator 84 with the holding coil switch 123inside the solenoid housing 82. In particular this resilience can beaccomplished by providing a spring 85A in the cable 80 that yields andthereby extends the cable 80 at a higher tensile force than thatrequired to depress the brake pedal 42. This way when the solenoid 72 isactivated the brake pedal 42 yields first and applies the brake 42.Thereafter if further travel is required for the actuator 84 to makeeffective contact with the holding coil switch 123 inside the housing82, the spring 85B yields to enable the actuator 84 to travel the fulldistance to the holding coil switch 123. As travel of brake pedal 42 canvary over a period of time while the vehicle 12 is in general use, thisfeature is very useful in accommodating wear in the brakes of a vehicleover time. It also provides some tolerance when the system 10 isinitially installed and has the result that the system can accommodateless than perfect installation.

The operation of the brake applicator 26 is controlled by the controller20 independently of the driver of the vehicle 12 and it takes placeautomatically and without any driver intervention. In particular whenthe controller 20 generates an accident prevention response signal thisis communicated to the brake applicator 26 which is activated andimmediately applies the brakes. It will be appreciated that the brakeapplicator 26 does not interfere in any way with the factory installedbrake system of a commercial vehicle. This is very important as amanufacturer's warranty would be voided by any interference with theworking mechanisms of a vehicle's brake. The brake applicator 26described above does not interfere in any way with the normal operationof the brake. It merely provides an additional way of applying thebrakes of the vehicle 12 that is independent of driver operation. Thesystem 10 also includes control wiring 88 extending from the controller20 to the brake applicator 26 as is shown in the drawings for enablingthe controller to send an accident prevention response signal to theapplicator 26.

The description above and the drawing show the sensors 15, 50 hard wiredto the controller 20. They also show the controller 20 hard wired to thealarms and the brake applicator. Instead the sensors, alarms and brakeapplicator could be wirelessly coupled to the controller 20 by means ofany wireless communication means including radio and fibre optic.

In use as shown in FIG. 12 a typical scenario where the system 10 mightbe used is where a vehicle is parked in a driveway and has to reversethe vehicle along the driveway to get onto a road. The system 10 isarmed when the driver of the motor vehicle 12 engages reverse gear andthus use of the system commences at this point. Once the system 10 isarmed the IR sensor 15 can sense passive IR and generate a mammalrecognition signal and the sonar sensors 50 can sense objects usingsound waves and generate an object recognition signal. When either ofthese signals is generated it is sent to the controller 20 whichgenerates an accident prevention response signal. The signal isgenerated by whichever of the IR sensor 15 and the sonar sensors 50first identify a mammal or an object respectively. If the IR sensor 15does not recognise a mammal in the vehicle's path the sonar sensors canstill recognise the object independently of the IR sensor and send theappropriate signal to the controller to trigger the accident preventionresponse signal.

The accident prevention response signal is sent to the horn 58 and alarm60 which are activated, and also to the brake applicator 26 which actsto immediately apply the brakes of the vehicle independently of thedriver. This stops the vehicle 12 if it is moving, or gets it to remainstationary, if it was not already moving as the case may be. It is to benoted that the system does not rely on the driver of the vehicle seeingthe child or applying the brake. Instead it relies on an automaticbraking action and on automatic generation of an alarm which can warnnot only the driver but other people outside of the vehicle 12 of thedanger as well. Thus the system 10 is not solely dependent on the IRsensor 15 or on the sonar sensors 50. It relies on the object beingsensed by at least one of these types of sensors and this significantlyenhances the reliability of the system 10.

FIG. 13 illustrates an accident prevention system in accordance withanother embodiment of the invention. As this system has manysimilarities to the system described above with reference to FIGS. 4 to11, the same reference numerals will be used to refer to the samecomponents unless otherwise indicated. Further the following descriptionwill focus solely on the differences between this embodiment and theearlier embodiment.

The FIG. 13 embodiment has a sonar sensor arrangement 16 comprising aplurality of sonar sensors 50 spaced apart long the rear end 38 of thevehicle body 30 but it does not have an IR sensor arrangement. The sonarsensors 50 can generate an object recognition signal and send it to thecontroller 20 and the controller 20 can generate an accident preventionresponse signal in response thereto. The system 10 does not have an IRsensor and cannot sense passive IR or body heat of a mammal. Thus thesystem 10 relies solely on the sonar sensors 50 to sense an object inthe path of vehicle and report it to the controller 20 which thereforewill respond in the same way as described above and apply the brakes andthe alarms without the intervention of the driver.

In a variation of the FIG. 13 embodiment the sensor arrangement is aradar sensor arrangement which pulses out radio waves and senses whenthey return to the sensor. The time taken for a pulse to return enablesthe distance of the sensed object from the sensor to be determined inthe same way that this is done with sonar sensors. The radar sensorslook the same as the sonar sensors shown in FIG. 13. Otherwise thissystem works in the same way as the system described immediately usingsonar sensors. In another variation of the FIG. 13 embodiment the sensorarrangement is a microwave sensor arrangement which pulses outmicrowaves and senses when they return to the sensor. The time taken fora pulse to return enables the distance of the sensed object from thesensor to be determined in the same way that this is done with sonarsensors. Otherwise this system works in the same way as the systemdescribed immediately using sonar sensors.

FIG. 14 illustrates an accident prevention system in accordance withanother embodiment of the invention. As this system has manysimilarities to the system described above with reference to FIGS. 4 to11, the same reference numerals will be used to refer to the samecomponents unless otherwise indicated. Further the following descriptionwill focus solely on the differences between this embodiment and theearlier embodiment.

The embodiment in FIG. 14 comprises an IR sensor arrangement 14 thatcomprises two laterally spaced IR sensors 90, 92 that are mountedtowards the rear end 38 of the vehicle body 12. As shown in the drawingsthe IR sensors 90, 92 are mounted on the mud flaps of the rear wheels 32of the vehicle 12 and face in a rearward direction. The sensors 90, 92are positioned close to the ground and also face at an angle downtowards the ground. The system also includes a controller 20 which isoperatively coupled to the IR sensors 90, 92 by wiring 93 mounted in thetrunk adjacent the rear end 38 of the vehicle 12. The controller 20 inturn is operatively connected to an alarm 58 and to the brake applicator26 as described above.

As a result when the when the IR sensor arrangement 14 senses thethermal signature of a mammal in an IR sensing zone behind the vehicle12 it sends a mammal recognition signal to the controller 20. Inresponse to receiving this signal the controller 20 generates anaccident prevention response signal that is sent to the brake applicator26 and applies the brakes and causes the siren 58 to sound. In avariation of this embodiment the IR sensor arrangement includes a singlecentrally mounted IR sensor 14 which is shown in dotted lines on therear end of the vehicle 12.

FIGS. 15 and 16 illustrate an accident prevention system in accordancewith another embodiment of the invention. As this system has manysimilarities to the system described above with reference to FIGS. 4 to11, the same reference numerals will be used to refer to the samecomponents unless otherwise indicated. Further the following descriptionwill focus solely on the differences between this embodiment and theearlier embodiment.

The system contains all the features of the system in FIG. 4. The IRsensors 15 and the sonar sensors 50 on the rear end 38 of the vehicle 12work in the same way as described above with reference to FIG. 4.Further the accident prevention responses taken by the system 10 are thesame as those described above with reference to FIG. 4.

In addition the system has a further IR sensor arrangement comprising asingle IR sensor 94 mounted on the front end 36 of the vehicle 12 thatcan sense a mammal in an IR sensing zone in front of the vehicle. Thesensor 94 is operatively connected to the controller 20 by means ofwiring 96. The controller 20 is programmed so that the sensor 94 isarmed when the driver of the vehicle 12 engages forward gear and thevehicle 12 travels at a speed of 0-5 kph. Once the speed of the vehicleincreases above 5 kph, the sensor 94 is disarmed. This system 10therefore is able to sense a mammal that is positioned in front of thevehicle 12 particularly towards the sides thereof, when the vehicle istravelling slowly in a forward direction. The inventor has identifiedthis as a blind spot where it is difficult for a driver to see a smallchild.

FIG. 17 illustrates an accident prevention system in accordance withanother embodiment of the invention. As this system has manysimilarities to the system described above with reference to FIGS. 4 to11, the same reference numerals will be used to refer to the samecomponents unless otherwise indicated. Further the following descriptionwill focus solely on the differences between this embodiment and theearlier embodiment.

The system 10 in FIG. 17 includes an IR sensor arrangement 14 and acontroller 20 which in turn is operatively connected to a sound alarmthat is a siren 58 by means of wiring 59. While a sensor arrangementhaving a single IR sensor that is centrally mounted has been shown, asensor arrangement comprising two laterally spaced IR sensors like thoseshown in FIG. 14 could equally be used. This system can detect apresence of a mammal in a sensing zone and generate mammal recognitionsignal which is sent to the controller 20. On receiving this signal thecontroller 20 generates an accident prevention response signal whichcauses the alarm to sound. This warns bystanders and the driver of therisk of an accident so that they and particularly the driver can takeaction to avoid an accident. However it does not have any sonar sensorsfor sensing an object behind the vehicle and it does not have thecapability of being able to automatically apply the brakes of thevehicle when the controller generates an accident prevention responsesignal.

FIG. 18 illustrates an accident prevention system in accordance withanother embodiment of the invention. As this system has manysimilarities to the system described above with reference to FIGS. 4 to11, the same reference numerals will be used to refer to the samecomponents unless otherwise indicated. Further the following descriptionwill focus solely on the differences between this embodiment and theearlier embodiment.

The system in FIG. 18 has an IR sensor arrangement much like the FIG. 17embodiment. It also has a controller 20 like the FIG. 17 embodiment andan audio alarm that is a horn 58 like the FIG. 17 embodiment. The maindifference between the FIG. 18 and FIG. 17 embodiments is that thesystem in FIG. 18 has a sonar sensor arrangement 16 in addition to theIR sensor arrangement 14. The sonar sensor arrangement 16 comprisesindividual sonar sensors 50 and is operatively connected to thecontroller 20 in parallel with the IR sensor arrangement 14 andgenerates an object recognition signal when it senses an object within asensing zone. When this occurs an object recognition signal is sent tothe controller 20 which generates an accident prevention responsecausing the alarm 58 to sound which warns the driver and other people ofa risk of a collision. Thus FIGS. 17 and 18 illustrate more basicembodiments of the invention that are able to sense a mammal such as achild in the IR sensing zone which is in the path of a reversing vehicleand then cause a siren to sound to warn people in the vicinity of thevehicle and also the driver of the vehicle.

FIG. 19 illustrates a vehicle towing a trailer where both the towingvehicle and the trailer have been fitted with the system. In thesedrawings the same reference numerals are used to refer to the towingvehicle and the components of the system 10 on the vehicle 12 as in FIG.4A above. In the drawings the trailer is referred to generally by thereference numeral 100.

The towing vehicle 12 has an IR sensor 14 and a plurality of sonarsensors 50 mounted on its bumper 48. The towing vehicle also has acontroller 20, an alarm 58 and a brake applicator 26. Further as shownin FIGS. 4A, 4B and 19, the towing vehicle has a tow hitch 102 and aservices socket 104 on its rear end 38.

The trailer 100 comprises a trailer body 106 mounted on wheels 108 and adraw pole 110 at a front end of the trailer 100. The trailer 100 alsohas a rear end 112 and an arrangement of sensors that comprises, acentrally mounted IR sensor 114 and a plurality of sonar sensors 116,spaced apart across the width of the rear end 112. These sensors 114 and116 function in the same way as the sensors 14 and 50 on the vehicle 12.The trailer also has a controller 118 mounted thereon that isoperatively connected to the sensor 114 by means of wiring 122 and thesensors 116 are connected to the controller 118 by means of furtherwiring 124.

The system 10 has a services plug 120 on the draw pole 110 and wirings126 and 127 for operatively connecting the controller 118 on the trailer100 to the horn 58 and/or the alarm 60 on the vehicle 12. The system 10has another wiring 128 for connecting the controller 118 to the brakeapplicator 26 on the vehicle 12. The wirings 126, 127 and 128 extendfrom the controller 118 and are routed along the trailer 100 and alongthe draw pole 110 and then coupled to the services plug 120. Theservices socket 104 has corresponding wirings operatively connectingthem to the alarms 58, 60 and brake applicator 26.

The controller 20 is operatively coupled to the services socket 104 onthe vehicle 12 such that when the services plug 120 is plugged thereinthe sensors 15, 50 on the vehicle 12 are effectively disarmed. It isnecessary to engineer the system 10 to do this because otherwise thepresence of the trailer 100 would be sensed by the sensors 15 and 50when the driver engaged reverse gear and this would urgently apply thebrakes of the vehicle 12.

When the services plug 120 is plugged into the services socket 104 thewiring 126 and 127 is indirectly operatively connected to the alarms 58and 60 on the vehicle 12. Similarly the wiring 128 is also indirectlyoperatively connected to the brake applicator 26 on the vehicle 12. Thesensors 114 and sonar sensors 116 sense for objects in a sonar sensingzone behind the trailer 100. When the sensors on the trailer identify anobject meeting certain conditions they generate the same recognitionsignals as the sensors 15, 50 on the vehicle 12 and these are sent tothe controller 20 on the vehicle 12.

In use the system 10 functions much like the system described above withreference to FIG. 4. The system is armed when the vehicle 12 engagesreverse gear, and the sensors 114 and 116 on the rear end of the trailer100 start sensing for objects behind the rear end 112 of the trailer100. The sensors 114 sense for mammals in an IR sensing zone and thesonar sensors 116 also sense for objects in a sonar sensing zone behindthe trailer 100. When the sensors on the trailer identify a mammal or anobject respectively they generate the same recognition signals as thesensors 15, 50 on the vehicle 12 and these are sent to the controller 20on the vehicle 12. For example if a small child is sensed by the sensors114 or 116 on the trailer 100 in the path of the trailer 100 when thetowing vehicle 12 is in reverse gear, the sensors 114 and 116 will senda recognition signal to the controller 118. The controller 118 will thensend an accident prevention response signal to the horn 58 and alarm 60and the brake applicator 26 on the main vehicle 12 which will then raisethe alarm and brake the vehicle 12. As described above the sensors 15and 50 on the rear end 38 of the vehicle 12 are disarmed when theservices coupling 120 on the trailer 100 is coupled to the servicessocket 104 on the rear of the towing vehicle 12. This stops thesesensors sensing the presence of the trailer 100 behind the vehicle 12.

An advantage of the system described above with reference to thedrawings and also a motor vehicle incorporating the system is that it isable to recognise a risk of accident condition independently of theactions of any human being. It operates quite independently of thedriver and does not rely on the driver at all for it to work. Ashortcoming of prior art systems described above is that they rely onthe driver for their efficacious operation. Further the system includesa loud audio alarm that sounds outside of the driver's cabin and warnspeople in the general area of the vehicle of the imminent danger.Further the accident brake applicator causes the brakes of the vehicleto be applied immediately when it receives a signal to do so quiteindependently of the actions of the driver. This stops the vehicleimmediately so that it cannot run over anyone behind the vehicle.Therefore related to the first advantage is the subsidiary advantagethat the system immediately applies the brakes of the vehicle, eitherstopping it if it is moving in the first place or bringing it to a haltif it is already moving.

Another advantage of some forms of the system described above withreference to the drawings is that it uses a passive sensor whichoperates by sensing passive IR energy that is radiated by a warm bodysuch as a human body. It does not radiate its own energy and then sensereflected energy. A related advantage is that this system is veryreliable at sensing human bodies within the reversing zone when thevehicle is either stationary or travelling at a slow speed. A furtheradvantage is that IR discriminates between human bodies and inanimateobjects such as walls and posts.

A yet further advantage of the systems that use both sonar and IRsensors described above with reference to the drawings is both of thesetypes of sensors sense for a small child in the path of a reversingvehicle. These two types of sensors work on different principles andthereby increase the chance of sensing a child in the path of thevehicle and this makes the system more reliable than a system using justone type of sensor.

A yet further advantage is that the system 10 can be installed on amotor vehicle 12 either during its manufacture or it can be retrofittedafter the vehicle 12 has been sold. For example the system can easily beproduced as an aftermarket product and be retrofitted to an existingvehicle. Yet further the system uses fairly basic components that can bebought off the shelf and is capable of reliable and trouble freeoperation. Yet further the system can be manufactured and supplied tothe market at a reasonable cost.

A yet further advantage of the system described above is that it willreduce the risk of reversing accidents in driveways causing death orinjury to small children. This will reduce the road trauma that iscaused by reversing accidents around the world each year.

It will of course be realized that the above has been given only by wayof illustrative example of the invention and that all such modificationsand variations thereto, as would be apparent to persons skilled in theart, are deemed to fall within the broad scope and ambit of theinvention as is herein set forth.

1. A method for preventing a reversing accident where a vehicle that isreversing at low speed collides with a person in the path of travel ofthe vehicle, the method comprising: sensing an object in the path oftravel by means of a sensor arrangement that generates an objectrecognition signal when the sensor arrangement senses an objectsatisfying a predetermined condition; sending the object recognitionsignal to a controller that is operatively coupled to the sensorarrangement; and sending an accident prevention response signal from thecontroller to a brake applicator on receiving the object recognitionsignal which then applies the brake of the vehicle whereby to resistmovement of the vehicle.
 2. A method for preventing a reversing accidentaccording to claim 1, wherein the sensor arrangement comprises at leastone IR sensor on a rear end of the vehicle, and sensing an objectcomprises passive sensing of IR heat from a mammal with said IR sensorand generating an object recognition signal when it senses an objectsatisfying the condition that it radiates IR heat corresponding to amammal
 3. The method for preventing a reversing accident according toclaim 1, wherein the sensor arrangement comprises a reflected pulsesensor arrangement on a rear end of the vehicle, and sensing an objectcomprises transmitting pulses of electromagnetic radiation away from therear end, and sensing return pulses returning to the sensor arrangement,and generating an object recognition signal comprises sensing when anobject is within a predetermined range of the rear end of the vehicle.4. The method for preventing a reversing accident according to claim 3,wherein transmitting pulses of electromagnetic radiation away from therear end of the vehicle comprises transmitting pulses of sound waves orradio waves or microwaves away from the rear end of the vehicle.
 5. Themethod for preventing a reversing accident according to claim 1, whereinthe sensor arrangement comprises an IR sensor arrangement and areflected pulse sensor arrangement that are mounted on the rear end ofthe vehicle, and sensing an object comprises: passive sensing of IR heatfrom a mammal with said IR sensor and generating an object recognitionsignal when it senses an object satisfying the condition that itradiates IR heat corresponding to a mammal, and transmitting pulses ofelectromagnetic radiation away from the rear end of the vehicle andsensing return pulses returning to the sensor arrangement, andgenerating an object recognition signal comprises sensing when an objectis within a predetermined range of the rear end of the vehicle.
 6. Themethod for preventing a reversing accident according to claim 1, whichalso includes sending each accident prevention response signal to analarm which then issues an alarm signal.
 7. The method for preventing areversing accident according to claim 1, wherein applying the brake ofthe vehicle comprises passing an electric current through a solenoid todisplace a cable which is operatively connected to a brake pedal of afoot brake whereby to displace the brake pedal downward to apply thefoot brake.
 8. An accident prevention system for use on a vehiclecomprising a front end and a rear end, the accident prevention systemcomprising: a sensor arrangement for mounting on the vehicle for sensingan object rearward of the rear end of the vehicle, and that generates anobject recognition signal when the sensor arrangement senses an objectsatisfying a predetermined condition; a controller that is operativelycoupled to the sensor arrangement and that generates an accidentprevention response signal on receiving an object recognition signalfrom the sensor arrangement; and a brake applicator that is operativelycoupled to a brake of the vehicle in use, the brake applicator isoperatively connected to the controller and applies the brake of thevehicle when the controller generates the accident prevention responsesignal whereby to resist movement of the vehicle.
 9. The accidentprevention system for use on a vehicle according to claim 8, wherein thesensor arrangement that comprises at least one IR sensor that is mountedon the rear end of the vehicle that senses heat and generates an objectrecognition signal when it senses an object satisfying the conditionthat it radiates IR heat corresponding to a mammal
 10. The accidentprevention system for use on a vehicle according to claim 8, wherein thesensor arrangement comprises a reflected pulse sensor arrangement thattransmits pulses of electromagnetic radiation away from the rear end ofthe vehicle and senses return pulses returning to the sensorarrangement, and the sensor arrangement generates an object recognitionsignal, when the sensor arrangement senses an object satisfying thecondition that the object is within a predetermined range of the rearend of the vehicle, and sends the object recognition signal to thecontroller.
 11. The accident prevention system for use on a vehicleaccording to claim 8, wherein the sensor arrangement comprises: an IRsensor arrangement that senses IR heat and that generates an objectrecognition signal when the IR sensor arrangement senses an objectsatisfying the condition that it radiates IR heat corresponding to amammal, and sends it to the controller; and a reflected pulse sensorarrangement that transmits pulses of electromagnetic radiation away fromthe rear end of the vehicle and senses return pulses returning to thesensor arrangement, and the sensor arrangement generates an objectrecognition signal, when it senses an object satisfying the conditionthat it is within a predetermined range of the rear end of the vehicle,and sends the object recognition signal to the controller.
 12. Theaccident prevention system for use on a vehicle according to claim 11,wherein the IR sensor arrangement comprises one or more passive IRsensors and the reflected pulse sensor arrangement comprises a pluralityof sonar sensors.
 13. The accident prevention system for use on avehicle according to claim 8, wherein the brake applicator comprises asolenoid that is operatively connected to the controller, a brakemounting member for operatively mounting to a foot brake of the vehiclein use, and a cable operatively coupling the brake mounting member tothe solenoid.
 14. The accident prevention system for use on a vehicleaccording to claim 8, further comprising an alarm that is operativelyconnected to the controller, and wherein the alarm issues an alarmsignal on receiving an accident prevention response signal from thecontroller.
 15. The accident prevention system for use on a vehicleaccording to claim 14, wherein the controller is a central processingunit contained within a control housing, and wherein the CPU is wired tothe sensor arrangement and the CPU is wired to the brake applicator andto the alarm.
 16. A vehicle comprising an accident prevention systeminstalled thereon, comprising: a vehicle body comprising a front end anda rear end mounted on ground engaging formations that permit the vehiclebody to travel across a surface, the vehicle comprising at least onebrake for stopping the vehicle; a sensor arrangement mounted on thevehicle for sensing an object rearward of the rear end of the vehicle,and that generates an object recognition signal when the sensorarrangement senses an object satisfying a predetermined condition; acontroller that is operatively coupled to the sensor arrangement andthat generates an accident prevention response signal on receiving anobject recognition signal from the sensor arrangement; and a brakeapplicator that is operatively coupled to a brake, and the brakeapplicator is operatively connected to the controller and applies thebrake when the controller generates the accident prevention responsesignal whereby to resist movement of the vehicle.
 17. A vehiclecomprising an accident prevention system installed thereon according toclaim 16, wherein the sensor arrangement comprises an IR sensorarrangement that senses IR heat and that generates an object recognitionsignal when it senses an object satisfying the condition that itradiates IR heat corresponding to a mammal, and sends it to thecontroller.
 18. A vehicle comprising an accident prevention systeminstalled thereon according to claim 16, wherein the sensor arrangementcomprises a reflected pulse sensor arrangement that transmits pulses ofelectromagnetic radiation away from the rear end of the vehicle andsenses return pulses returning to the sensor arrangement, and the sensorarrangement generates an object recognition signal when the sensorarrangement senses an object satisfying the condition that the object iswithin a predetermined range of the rear end of the vehicle, and sendsthe object recognition signal to the controller.
 19. A vehiclecomprising an accident prevention system installed thereon according toclaim 18, wherein the reflected pulse sensor arrangement comprises oneor more reflected pulse sensors that are positioned on the rear end ofthe vehicle, and wherein the reflected pulse sensor arrangementgenerates an object recognition signal when the reflected pulse sensorarrangement identifies objects within a range that is a distance ofbetween 0.5 meters and 2.0 meters from the rear end of the vehicle. 20.A vehicle comprising an accident prevention system installed thereonaccording to claim 19, wherein the one or more reflected pulse sensorscomprises sonar sensors that pulse sound waves, or radar sensors thatpulse radio waves, or microwave sensors that pulse microwaves, and thesensors sense when the reflected waves return to the sensor arrangement.